Ka, the time-travelling cat, leaves the word TENOCHTITLAN on Topher's computer. He is horrified. That was the home of the blood-thirsty Aztecs. When Topher travels to sixteenth century Mexico he finds Ka, and he makes a new friend, the Aztec girl, Patti. Can he stop the Aztecs sacrificing her. Can he save Ka from terrible danger? Can he escape before the Spanish conquistadores destroy the beautiful city of Tenochtitlan? In this fast-moving adventure Topher meets Montezuma, the legendary Aztec chief, and Cortes, the famous Spanish explorer.